FXUS66 KMTR 060834 AFDMTR Area Forecast Discussion National Weather Service San Francisco CA 134 AM PDT Fri Sep 6 2024 ...New SYNOPSIS, SHORT TERM, LONG TERM... .SYNOPSIS... Issued at 133 AM PDT Fri Sep 6 2024 Hot and dry conditions again for Friday, resulting in a moderate to major risk of heat-related illness and near critical fire weather conditions. A pronounced cooling trend starts on Saturday and continues into next week. && .SHORT TERM... (Today and tonight) Issued at 133 AM PDT Fri Sep 6 2024 Today is forecast to be the last hot day across the interior, with slight cooling tomorrow. Expecting temperatures to range from 95- 105 degrees across the the far interior and in the higher elevations, 80's to mid 90's inland just away from the coast, and upper 60's to mid 80's near the coast. As such, moderate HeatRisk persist for inland areas where a Heat Advisory remains in effect until 8 PM this evening. With high pressure aloft, dry conditions will persist above the 500 foot marine layer as minimum humidities this afternoon will lower to 10-30% range. Overnight humidity recoveries will be slightly higher tonight except for the highest peaks. Nevertheless, we are still anticipating elevated to near critical fire weather conditions across the interior on Friday. Tonight, expect minimum temperatures to lower into the low-to-upper 50's near the coast and adjacent coastal valleys, near 60 degrees in the South Bay and Santa Clara Valley, and the upper 60's to upper 70's in the higher elevations. && .LONG TERM... (Saturday through Thursday) Issued at 133 AM PDT Fri Sep 6 2024 A significant pattern change will bring relief to the region on Saturday as the ridge flattens in response to an upper level trough digging out of the Gulf of Alaska and into the eastern Pacific. By Sunday, onshore flow will increase and bring temperatures back to near seasonal averages which will continue into early next week. Onshore winds will increase also with breezy to locally gusty conditions in the gaps and passes. From previous forecaster: "Heading into the later part of next week, model clusters are starting to hint at a low pressure system that could bring some chances for rain to the North Bay. That said, the model clusters continue to diverge on location and timing, so uncertainty towards this part of the period remains high." && .AVIATION... (06Z TAFS) Issued at 1043 PM PDT Thu Sep 5 2024 IFR to LIFR CIGs expected overnight with elevated fog potential across portions of the North Bay and the Monterey Bay region. Night Fog shows stratus starting to move inland across the North Bay and through the Golden Gate with low level CIGs to reach most airports by 07-09Z with the potential for an earlier arrival at MRY and SNS. CIGs are expected to dissipate by mid to late morning with most sites expected to clear between 16-18Z. Moderate onshore flow generally persists through the period with winds expected to weaken and become light overnight. Vicinity of SFO...IFR CIGs expected overnight with VFR returning by mid to late morning. Some potential for visibility to drop overnight at SFO but not currently anticipating fog to develop. Moderate confidence in timing of stratus arrival with Night Fog showing low level clouds currently pushing through the Golden Gate. Will continue to monitor the trends to potentially push back stratus arrival by an hour or two. Overnight winds will generally stay between 8 to 10 knots with gustier winds up to 20 knots returning early tomorrow afternoon. SFO Bridge Approach...Similar to SFO. Monterey Bay Terminals...IFR to LIFR CIGs expected overnight with elevated fog potential at MRY. Night Fog shows an eddy over the Monterey Bay starting to fill in with low level cloud cover gradually shifting inland. KOAR is already socked in and shows overcast conditions at 300ft which increases confidence that LIFR CIGs will develop tonight. Stratus is expected to reach MRY and SNS within the next 1 to 2 hours with fog chances increasing after 08- 10Z. CIGs are expected to clear by late tomorrow morning and an early return of stratus is expected tomorrow evening. Winds generally stay out of the northwest but may temporarily become light and variable overnight. Moderate northwest flow will return during && .MARINE... (Tonight through next Wednesday) Issued at 1043 PM PDT Thu Sep 5 2024 Fair weather continues as high pressure persists over the region. Winds will generally be moderate to fresh and west to northwest, with moderate seas. It is not until the middle part of next week that winds and seas begin to increase to become strong and out of the northwest. && .MTR WATCHES/WARNINGS/ADVISORIES... CA...Heat Advisory until 8 PM PDT this evening for CAZ502>504-506-510- 512>518. PZ...None. && $$ SHORT TERM...RGass LONG TERM....RGass/DialH AVIATION...Canepa MARINE...Canepa Visit us at www.weather.gov/sanfrancisco Follow us on Facebook, Twitter, and YouTube at: www.facebook.com/nwsbayarea www.twitter.com/nwsbayarea www.youtube.com/nwsbayarea